U.S. patent number 11,220,662 [Application Number 16/063,071] was granted by the patent office on 2022-01-11 for laundry sheet comprising functional granules.
This patent grant is currently assigned to LG Household & Health Care Ltd.. The grantee listed for this patent is LG Household & Health Care Ltd.. Invention is credited to Kyung-On Cha, Min-Seok Cho, Mun-Seong Jo, Jae-Hyun Kim.
United States Patent |
11,220,662 |
Cho , et al. |
January 11, 2022 |
Laundry sheet comprising functional granules
Abstract
The present invention provides a laundry sheet wherein one or
more component selected from a group consisting of a builder, an
enzyme, a bleaching agent and a bleach activator is contained as a
granule in a laundry film prepared using a laundry detergent
component and a film-forming water-soluble polymer. The laundry
sheet of the present invention completely dissolves in water and
thus does not need to be removed after laundering. In addition, the
laundry sheet of the present invention has superior cleaning
performance, is convenient to use and has superior storage
stability.
Inventors: |
Cho; Min-Seok (Daejeon,
KR), Jo; Mun-Seong (Daejeon, KR), Cha;
Kyung-On (Daejeon, KR), Kim; Jae-Hyun (Daejeon,
KR) |
Applicant: |
Name |
City |
State |
Country |
Type |
LG Household & Health Care Ltd. |
Seoul |
N/A |
KR |
|
|
Assignee: |
LG Household & Health Care
Ltd. (N/A)
|
Family
ID: |
59514761 |
Appl.
No.: |
16/063,071 |
Filed: |
December 16, 2016 |
PCT
Filed: |
December 16, 2016 |
PCT No.: |
PCT/KR2016/014803 |
371(c)(1),(2),(4) Date: |
June 15, 2018 |
PCT
Pub. No.: |
WO2017/105131 |
PCT
Pub. Date: |
June 22, 2017 |
Prior Publication Data
|
|
|
|
Document
Identifier |
Publication Date |
|
US 20200010784 A1 |
Jan 9, 2020 |
|
Foreign Application Priority Data
|
|
|
|
|
Dec 17, 2015 [KR] |
|
|
10-2015-0180978 |
May 31, 2016 [KR] |
|
|
10-2016-0067653 |
|
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
C11D
17/06 (20130101); C11D 1/29 (20130101); C11D
3/3905 (20130101); C11D 3/386 (20130101); C11D
3/10 (20130101); C11D 3/38609 (20130101); C11D
3/37 (20130101); C11D 3/3753 (20130101) |
Current International
Class: |
C11D
17/06 (20060101); C11D 1/14 (20060101); C11D
3/37 (20060101); C11D 3/386 (20060101); C11D
1/29 (20060101); C11D 3/10 (20060101) |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
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|
|
1186650 |
|
Mar 2002 |
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EP |
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S58135794 |
|
Aug 1983 |
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JP |
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10-72593 |
|
Mar 1998 |
|
JP |
|
2011-116430 |
|
Jun 2011 |
|
JP |
|
1999-0030414 |
|
Apr 1999 |
|
KR |
|
2004-0067668 |
|
Jul 2004 |
|
KR |
|
2010-0107284 |
|
Oct 2010 |
|
KR |
|
20100107283 |
|
Oct 2010 |
|
KR |
|
2012-0021449 |
|
Mar 2012 |
|
KR |
|
2013-0124261 |
|
Nov 2013 |
|
KR |
|
2014-0100129 |
|
Aug 2014 |
|
KR |
|
20140102458 |
|
Aug 2014 |
|
KR |
|
2015086692 |
|
Jun 2015 |
|
WO |
|
Other References
International Search Report From PCT/KR2016/014803 dated Apr. 19,
2017. cited by applicant .
Extended European Search Report including Written Opinion for
Application No. EP16876073.4 dated May 24, 2019, pp. 1-6. cited by
applicant.
|
Primary Examiner: Douyon; Lorna M
Attorney, Agent or Firm: Lerner, David, Littenberg, Krumholz
& Mentlik, LLP
Claims
What is claimed is:
1. A laundry sheet comprising: an active component for laundering,
wherein the active component is an enzyme, and a laundry film
formed by mixing a laundry detergent component and a film-forming
water-soluble polymer, wherein the laundry detergent component is
sodium lauryl sulfate, wherein the active component for laundering
is a granule, and the granule is contained and distributed between
polymer matrices on at least one side of the laundry film, wherein
the granules are added after the mixing of the laundry detergent
component and the film-forming water-soluble polymer, wherein the
granule is an assemblage of an amorphous particle, wherein the
film-forming water-soluble polymer is polyvinyl alcohol having an
average degree of polymerization of 100-3000, and wherein the
granule has an average particle diameter of 0.5 mm to 2 mm.
2. The laundry sheet according to claim 1, wherein the enzyme is
one or more selected from a group consisting of a protein-degrading
enzyme, a lipid-degrading enzyme, a carbohydrate-degrading enzyme,
a cellulose-degrading enzyme, a mannan-degrading enzyme and a
pectin-degrading enzyme.
3. The laundry sheet according to claim 1, wherein the laundry film
is stacked to form a multi-layered structure.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
This application is a national phase entry under 35 U.S.C. .sctn.
371 of International Application No. PCT/KR2016/014803, filed Dec.
16, 2016, which claims priority to Korean Patent Application No.
10-2015-018097, filed Dec. 17, 2015 and Korean Patent Application
No. 10-2016-0067653, filed May 31, 2016, the disclosures of which
are incorporated herein by reference.
TECHNICAL FIELD
The present invention relates to a laundry sheet and a method for
preparing the same. Particularly, it relates to a laundry sheet
capable of increasing the effects of components contained in the
laundry sheet and stabilizing them and a method for preparing the
same.
BACKGROUND ART
At present, polymer films are widely used not only in industrial
fields such as precision chemical and electronic materials but also
in medical and personal care products such as cosmetics, etc. and
household articles such as everyday items. Examples of the polymer
films used in medical or cosmetic products include a poultice
sheet, an adhesive skin patch sheet, etc. wherein a water-insoluble
polymer film and a drug are stacked together on a substrate. The
polymer film forms a matrix and exhibits a controlled release
profile. In everyday items, polymer films are widely used as
packaging materials for packaging specific materials and active
components separately and thereby providing convenience of use. For
example, a polymer film is used as a material for packaging a
detergent composition such as a powder detergent and a detergent
separately. Korean Patent Publication No. 10-1999-0030414 uses a
polyvinyl alcohol film, a gelatin film, a starch film and a
cellulose film which are highly soluble in water as a packaging
material in order to prevent scattering of a powder detergent and
protect water quality by inducing use of an optimum amount. U.S.
Pat. No. 4,605,509, Japanese Patent Publication No. S58-135794 and
Korean Patent Publication No. 10-2004-0676668 disclose technologies
of packaging a liquid detergent and a fabric softener with a
water-soluble film.
However, when the water-soluble polymer film is used for separate
packaging, the packaged product may leak during storage or
transport and the active components may ooze to the film surface.
As a result, the storage stability of the product is degraded
significantly. In addition, when the water-soluble film is used as
a packaging material, it is designed to be stable against moisture
in the atmosphere and durable against the content. Due to this,
considerable time is required for dissolution at low temperature
and the film may remain without being completely dissolved.
To solve these problems, Korean Patent Publication No.
10-2013-0124261 provides a laundry sheet prepared by mixing an
active component for laundering such as a detergent in a
composition for forming a water-soluble polymer film and then
forming a film. However, when the sheet is prepared by removing a
solvent such as water from a solution containing a film-forming
water-soluble polymer, active components for laundering and the
solvent, stability may be decreased as an enzyme, a bleaching
agent, etc. among the active components for laundering contained in
the laundry sheet are activated and cleaning performance may not be
exerted effectively.
DISCLOSURE
Technical Problem
The present invention is directed to providing a laundry sheet
which is capable of effectively exerting the effect of one or more
active components for laundering selected from a group consisting
of a builder, enzyme, a bleaching agent and a bleach activator and
a method for preparing the same.
Technical Solution
The present invention provides a laundry sheet prepared using a
laundry detergent component and a film-forming water-soluble
polymer, wherein one or more component selected from a group
consisting of a builder, an enzyme, a bleaching agent and a bleach
activator is contained as a granule.
In the present invention, the one or more component selected from a
group consisting of a builder, an enzyme, a bleaching agent and a
bleach activator may be specifically a component which exerts an
effect by being activated together with water.
Hereinafter, the present invention is described in more detail.
The present invention provides a laundry sheet prepared using a
laundry film prepared by removing a solvent from a solution
containing a film-forming water-soluble polymer and the solvent. A
laundry sheet wherein the active component for laundering is
distributed in the laundry sheet in the form of a granule without
being dissolved is provided. The laundry sheet may be solidified
while maintaining a predetermined shape.
The inventors of the present invention have completed the present
invention in order to solve the problem that the active component
for laundering is activated during preparation of the laundry
sheet, making it difficult to exert full effect. It was confirmed
that better cleaning effect is achieved when the active component
for laundering is contained in the laundry sheet in the form of an
undissolved granule.
Definition of Terms
The term "film" used in the present disclosure may be interpreted
to mean a thin and flexible membrane or layer. The thickness is not
particularly limited and the shape of the film is not particularly
limited.
The term "laundry film" used in the present disclosure may be
interpreted to mean a film containing i) a laundry detergent
component, ii) a laundry softening component, iii) a perfume or iv)
two or more of them. Hereinafter, the laundry detergent component
may be understood to contain, in addition to the laundry detergent
component, a laundry softening component, a perfume or a mixture
thereof.
The laundry film may be formed using a solution obtained by mixing
a water-soluble polymer for forming the film and a laundry
detergent component, although not being limited thereto. The
thickness of the laundry film may be identical to that of the film
or may be greater or smaller than the thickness of the film. The
shape of the laundry film is not particularly limited.
The "film" and the "laundry film" may be formed by completely
drying a solution for preparing the film or the laundry film and
the solution may be in a semi-dried state. The semi-dried state may
mean a state wherein the film maintains the shape of a membrane
while containing water to some extent. For example, 70% or more,
specifically 80% or more, more specifically 90% or more, of water
may have been evaporated from the solution for preparing the film
or the laundry film.
The term "sheet" used in the present disclosure may refer to one in
which an active component for laundering is distributed on one
and/or both sides of a film or a laundry film in order to achieve
the purpose of the present invention. For example, the active
component for laundering may be one or more component selected from
a group consisting of a builder, an enzyme, a bleaching agent and a
bleach activator. Specifically, the active component for laundering
may be distributed in an undissolved state. That is to say, in the
present disclosure, the sheet is used in a meaning distinguished
form the film or the laundry film.
The sheet of the present invention may contain one laundry film or
may be provided as a form in which two or more films are stacked.
When the sheet of the present invention contains two or more films,
at least one of them is a laundry film. The sheet may be processed
to be provided to a consumer and the type of the sheet provided to
the consumer is not particularly limited.
The term "distribution" used in the present disclosure means the
presence of a specific active component for laundering in the form
of a granule (e.g., one or more component selected from a group
consisting of a builder, an enzyme, a bleaching agent and a bleach
activator) regularly or irregularly in/or a thin film formed from a
film-forming water-soluble polymer to have a predetermined tensile
strength.
DETAILED DESCRIPTION OF INVENTION
In an exemplary embodiment, the present invention provides a
laundry sheet wherein one or more component selected from a group
consisting of a builder, an enzyme, a bleaching agent and a bleach
activator is contained as a granule in a laundry film prepared
using a laundry detergent component and a film-forming
water-soluble polymer.
In a specific exemplary embodiment of the present invention, the
laundry sheet may be prepared by a method including:
(S1) a step of preparing a solution for preparing a laundry film by
dissolving a film-forming water-soluble polymer and a laundry
detergent component;
(S2) a step of forming a laundry film with the solution prepared in
the step (S1); and
(S3) a step of adding one or more component selected from a group
consisting of a builder, an enzyme, a bleaching agent and a bleach
activator in an undissolved state to the laundry film prepared in
the step (S2).
In the step (S1), the aggregated polymer chain of the film-forming
water-soluble polymer is disentangled. In the step (S3), the active
component for laundering in an undissolved state, e.g., one or more
component selected from a group consisting of a builder, an enzyme,
a bleaching agent and a bleach activator, is distributed between
the polymer chain.
In the step (S3), the one or more component selected from a group
consisting of a builder, an enzyme, a bleaching agent and a bleach
activator is added in an `undissolved state`. The term `undissolved
state` includes not only that 100% of the component is undissolved
but also that the component is partly dissolved. The term `partly
dissolved` means that 10% or less, 9% or less, 8% or less, 7% or
less, 6% or less, 5% or less, 4% or less, 3% or less, 2% or less or
1% or less, specifically 5% or less, of the component is
dissolved.
In the present invention, one or more component selected from a
group consisting of a builder, an enzyme, a bleaching agent and a
bleach activator is added in the form of a granule to be added in
an undissolved state.
In the step (S2), a laundry film is formed using the solution of
the step (S1). The one or more component selected from a group
consisting of a builder, an enzyme, a bleaching agent and a bleach
activator may be added to the laundry film in an undissolved state,
e.g. in the form of a granule. The type of the granule is not
limited as long as it remains undissolved in the laundry sheet
In another exemplary embodiment of the present invention, the
laundry sheet may be prepared by further stacking the laundry film
prepared in the step (S2). In the step (S3), the laundry film may
be further stacked after the one or more component selected from a
group consisting of a builder, an enzyme, a bleaching agent and a
bleach activator is distributed on one or both sides of the film in
an undissolved state. The further stacked laundry film may be
replaced with a film.
The inventors of the present invention have first identified that,
when the granule containing the active component for laundering
remains on the sheet surface without completely including inside
the sheet, the functionality of the laundry sheet may decrease as
the granule particle is detached from the sheet during storage and
transport. In addition, it was confirmed that, in that case, a
component that can cause skin irritation when the functional
granule directly contacts with skin may be exposed to the body part
of a user. To prevent this, the film or the laundry film may be
further stacked on the laundry sheet of the present invention.
Specifically, the method may further include (S4) a step of
preparing a film with a film-forming water-soluble polymer. The
film prepared in the step (S4) may be prepared with the same
film-forming water-soluble polymer as that used to prepare the film
of the step (S2) or a different film-forming water-soluble polymer.
The film of the step (S4) may or may not contain a laundry
detergent component.
The method may further include (S5) a step of attaching the film
(or laundry film) of the step (S4) to the film of the step (S3) in
the state where the one or more component selected from a group
consisting of a builder, an enzyme, a bleaching agent and a bleach
activator is undissolved.
The film (or laundry film) of the step (S3) on which the one or
more component selected from a group consisting of a builder, an
enzyme, a bleaching agent and a bleach activator is distributed in
an undissolved state may be referred to as a first film and the
film (or laundry film) added newly onto the first film may be
referred to as a second film.
Specifically, the film added in the step (S5) may have the same
area as the film prepared in the step (S2), although the size is
not limited thereto.
In the step (S5) of attaching the film, two sheets of the film may
be stacked and then bonded together. The bonding may be achieved by
using an adhesive, heat, ultrasonic waves, etc., although not being
particularly limited thereto. The bonding method is not specially
limited as long as the one or more component selected from a group
consisting of a builder, an enzyme, a bleaching agent and a bleach
activator can remain undissolved between the films.
In an exemplary embodiment, the present invention provides a
laundry sheet prepared by the method for preparing a laundry sheet
of the present invention.
In another exemplary embodiment of the present invention, the
laundry sheet may be prepared by stacking three sheets of the film
(or laundry film) such that the component in the form of a granule
remains undissolved between the films. For example, the laundry
sheet shown in FIG. 4 may be provided.
Specifically, the preparation method may include a drying step. The
reaction condition of the drying step may vary depending on the
process condition. The temperature of a drying furnace may be
40-120.degree. C., drying time may be 5-30 minutes and drying speed
may be 1-10 m/min. Specifically, the temperature of the drying
furnace may be 60-110.degree. C., the drying time may be 5-20
minutes and the drying speed may be 1-10 m/min.
Specifically, in the present invention, when the one or more
component selected from a group consisting of a builder, an enzyme,
a bleaching agent and a bleach activator is added as a granule, it
is necessary to control the water content of the film (or laundry
film) below a predetermined level in order to prevent it from being
dissolved in the film (or laundry film).
Specifically, the water content may be 30 wt % or less based on the
total weight of the film (or laundry film), although not being
limited thereto.
Accordingly, the one or more component selected from a group
consisting of a builder, an enzyme, a bleaching agent and a bleach
activator is added as a granule and the granule may be added any
time, e.g., before, during or after the drying, as long as it
remains undissolved after the film (or laundry film) is
prepared.
The film-forming water-soluble polymer used in the laundry sheet
according to the present invention may be one or more selected from
natural, semi-synthetic and synthetic polymers.
As the natural polymer, gelatin, pectin, dextran, hyaluronic acid
or a salt thereof, collagen, agar, a gum such as gum arabic,
xanthan gum, gum acacia, gum karaya, gum tragacanth and guar gum,
carrageenan, alginic acid, sodium alginate, etc. may be used.
As the semi-synthetic polymer, methyl cellulose, ethyl cellulose,
hydroxyethyl cellulose, sodium carboxymethyl cellulose, soluble
starch, dextrin, carboxymethyl starch, dialdehyde starch, etc. may
be used.
As the synthetic polymer, a widely known synthetic polymer such as
polyvinyl alcohol, polyvinylpyrrolidone, polyvinyl methacrylate,
polyacrylic acid and a salt thereof, polyethylene oxide, a
carboxyl-containing acryl resin, a carboxyl-containing polyester
resin, water-soluble polyamide, water-soluble polyurethane,
maltodextrin and polydextrose or a water-soluble synthetic polymer
prepared from a radical-polymerizable monomer may be selected. The
polymer synthesized from the radical-polymerizable monomer may be a
homopolymer or a copolymer of an ionic monomer and a nonionic
monomer.
As a specific example, the film-forming water-soluble polymer may
be polyvinyl alcohol (PVA). Specifically, polyvinyl alcohol having
a degree of saponification of 75-95% and an average degree of
polymerization of 100-3000 may be used to ensure solubility. If the
degree of saponification is below 75% or exceeds 95%, it does not
dissolve well in water due to low solubility. And, if the average
degree of polymerization is below 100, it is not easy to form a
film because the molecular weight is too small and the physical
properties of the film such as tensile strength, etc. are
unsatisfactory. If the average degree of polymerization exceeds
3000, water solubility is poor after film formation because the
molecular weight is too large.
The film-forming water-soluble polymer may be contained in an
amount of 5-80 wt %, specifically 10-60 wt %, more specifically
20-50 wt %, based on the total weight of the film (or laundry film)
after the drying. If the content of the water-soluble polymer is
lower than 5 wt %, it is difficult to form the film (or laundry
film) because the tensile strength of the laundry sheet is too
weak. If the content is higher than 80 wt %, the performance of the
laundry sheet is decreased because the content of the active
component is decreased relatively and the economic cost is
increased due to the increased content of the water-soluble
polymer.
Meanwhile, in the laundry sheet according to the present invention,
the `water solubility` of the film-forming water-soluble polymer
may be defined under the following measurement condition.
After adding a predetermined amount (5 g) of the film prepared with
the film-forming polymer to 500 mL of water and stirring on a
magnetic stirrer set to 500 rpm for 10 minutes, the prepared film
solution is filtered through filter paper with a maximum pore size
of 10 jam, water is dried from the collected filtrate and the
weight of the residual material is measured. If the weight is 70%
or larger, specifically 80% or larger, more specifically 90% or
larger, as compared to the initial weight of the film, the
film-forming polymer is defined as a film-forming water-soluble
polymer.
A film-forming water-dispersible polymer is also included in the
scope of the film-forming water-soluble polymer of the present
invention.
In the present disclosure, the term `water dispersibility` has the
following meaning. After adding a predetermined amount (5 g) of a
film to 500 mL of water and stirring on a magnetic stirrer set to
500 rpm for 10 minutes, the prepared film solution is filtered
through filter paper with a pore size of 10 jam, water is dried
from the collected filtrate and the change in weight is measured.
If the weight change is 30% or smaller, specifically 20% or
smaller, more specifically 10% or smaller, as compared to the
initial weight of the film, the film-forming polymer is defined as
a film-forming water-dispersible polymer.
Although the film-forming water-soluble polymer used in the present
invention has a film-forming property of forming a film matrix, the
entangled polymer chain of the film-forming water-soluble polymer
in the laundry sheet is disentangled again by a solvent during
cleaning. That is to say, the film-forming water-soluble polymer is
of a polymer chain type. When solidified, the polymer chain remains
assembled in an entangled state. And, when dissolved in a solvent,
the polymer chain is disentangled and another material can be
inserted between the polymer chain.
As the solvent used to prepare the laundry sheet according to the
present invention, water may be used to dissolve the water-soluble
polymer. Although a hydrophilic solvent such as an alcohol may also
be used, it is preferred to use water because the solubility of the
water-soluble polymer may decrease.
In the present invention, the `laundry detergent component` may be
a generally used anionic surfactant, nonionic surfactant or
zwitterionic surfactant and may also be a mixture of two or more of
them.
Representative examples of the anionic surfactant may include a
carboxylate compound such as soap, a higher alcohol, a higher alkyl
ester, a sulfuric ester salt compound obtained from sulfation of an
olefin, an alkylbenzenesulfonate, a sulfate compound including a
lauryl sulfate salt and a phosphate compound obtained from
phosphorylation of a higher alcohol.
For example, laurylbenzenesulfonic acid, an .alpha.-olefin
sulfonate, sodium lauryl sulfate, ethoxylated sodium lauryl
sulfate, a secondary alkanesulfonate, methyl ester sulfonate, etc.
may be used alone or as a mixture of two or more, although not
being limited thereto. Specifically, sodium lauryl sulfate may be
used as the anionic surfactant.
And, as the nonionic surfactant, a polyoxyalkylene alkyl phenyl
ether, a polyoxyalkylene alkyl ether, a polyoxyethylene
polyoxypropylene block polymer, a polyethylene glycol fatty acid
ester, a polyoxyethylene sorbitan fatty acid ester,
cocamidomonomethylamine, cocamidodimethylamine,
cocamidomonoethylamine, a fatty acid alkanolamine, an amine oxide,
an alkyl polyglucoside, a methyl polyethylene alkyl ether, a sugar
ether, etc. may be used alone or as a mixture of two or more,
although not being limited thereto. Specifically, a polyoxyalkylene
alkyl ether represented by Chemical Formula 1 or a polyoxyalkylene
alkyl phenylether represented by Chemical Formula 2 may be used.
C.sub.m--H.sub.2m+1--O--(CH.sub.2CH.sub.2O).sub.n--H [Chemical
Formula 1]
C.sub.mH.sub.2m+1C.sub.6H.sub.5--O--(CH.sub.2CH.sub.2O).sub.n--H
[Chemical Formula 2]
In Chemical Formula 1 and Chemical Formula 2, m is an integer from
5 to 21 and n is an integer from 1 to 20.
And, as the zwitterionic surfactant, an amine oxide, cocamidopropyl
betaine, etc. may be used alone or as a mixture of two or more,
although not being limited thereto.
The active components for laundering such as the builder, the
enzyme, the bleaching agent, the bleach activator, etc. exert
activity by reacting with water. If they are mixed together with
the film-forming water-soluble polymer and the laundry detergent
component, they are dissolved during the preparation process and
exert their activities. As a result, they cannot exhibit their
performance when the final product is used.
Accordingly, in the present invention, in order to solve the
problem of decreased performance of a specific active component for
laundering which exerts activity by reacting with water in the
water-soluble polymer film, the active component for laundering
prepared into a granule form is applied to the laundry sheet and/or
the composition for preparing the laundry sheet. That is to say, in
the present invention, the active component for laundering prepared
into a granule form is present between the polymer chain of the
laundry sheet in an undissolved state.
That is to say, the present invention provides a laundry sheet
prepared using a laundry detergent component and a film-forming
water-soluble polymer, wherein one or more component selected from
a group consisting of a builder, an enzyme, a bleaching agent and a
bleach activator is added as a granule.
Specifically, in the present invention, when the one or more
component selected from a group consisting of a builder, an enzyme,
a bleaching agent and a bleach activator is added as a granule, the
water content of the film (or laundry film) should be below a
predetermined level so that the component is not dissolved in the
film (or laundry film) and not activated before cleaning. The water
content may be specifically 30 wt % or lower based on the total
weight of the film, although not being limited thereto.
The inventors of the present invention have found out that, whereas
the components cannot exert their performance in the final product
if they are mixed in a water-soluble polymer solution during the
preparation of a laundry sheet because their activity is exerted
during laundry sheet preparation process, they can fully exert
their performance if they are added in the laundry sheet and/or the
composition for preparing the laundry sheet in an undissolved state
and have completed the present invention.
In the present invention, the granule is not limited to any shape.
That is to say, it is not limited in shape as long as the
components remain undissolved in the laundry sheet and is not
specially limited in size. That is to say, the granule includes any
one with irregular shape and size, commonly called a particle, a
powder, a grain, etc.
In the present invention, the granule is an assemblage of an
amorphous particle with no predetermined shape. In the present
disclosure, the granules of different sizes are represented by an
average particle diameter.
In the present invention, the shape of the granule may be a
spherical shape, a cylindrical shape, a splinter shape or a
combination thereof, although not being limited thereto.
It is obvious to those of ordinary skill in the art that the
`spherical shape` includes a shape which is not a perfect sphere.
That is to say, it includes a shape whose transverse and/or
longitudinal cross section is an ellipse rather than a perfect
circle and also includes a shape whose contour is regularly or
irregularly uneven rather than smoothly curved.
In the present disclosure, the term "average particle diameter"
means a particle size measured using a laser particle size
analyzer. In the particle size distribution measurement, the
determined diameter of the particle is an imaginary equivalent
diameter. When one of the measured physical properties of a
particle is similar to that of a sphere having a particular
diameter, this diameter is referred to as the equivalent diameter
of the particle. The laser particle size analyzer measures the
particle size using scattering property and the measured diameter
is an equivalent scattering diameter. That is to say, it is the
diameter of a sphere exhibiting the same scattering property.
In the present invention, the average particle diameter of the
granule may be 0.1-5 mm, specifically 0.3-3 mm, more specifically
0.5-2 mm.
In the present invention, the component that may be added in the
form of a granule may include a builder, an enzyme, a bleaching
agent, a bleach activator, a sterilizer/disinfectant, a perfume,
etc., although not being limited thereto.
The term "builder" used in the present disclosure means a hard
water softener. The builder refers to a material which sequesters
ions such as calcium, magnesium, etc. in hard water by
precipitating, removing through ion exchange or forming a chelate,
although not being limited thereto. That is to say, the builder
exerts its effect by being activated upon reaction with water.
When the builder is added to a water-soluble polymer solution in
the form of a powder during the preparation of a laundry sheet as
in the existing technology, the builder may be activated by water
contained in the water-soluble polymer solution during the
preparation of a sheet and, therefore, may not fully exert its
effect during cleaning. And, for PVA, it is difficult to prepare
the sheet due to gelation and salting out and solubility may
decrease. In order to solve this problem, the builder is added to
the laundry sheet in an undissolved state in the present invention.
Then, a large portion of the builder is activated during cleaning
and, therefore, significantly superior cleaning performance is
achieved as compared to when it is added to a water-soluble polymer
solution (see Table 3). In addition, sheet-forming property is
superior and the builder does not ooze to the surface (see Table
2).
Specifically, the builder that may be used in the present invention
may be an alkaline builder. One or more selected from a group
consisting of sodium hydroxide, sodium carbonate, sodium
bicarbonate, sodium metasilicate, alkaline sodium silicate, neutral
sodium silicate, sodium tripolyphosphate, sodium pyrophosphate,
sodium borate, zeolite (sodium aluminosilicate), sodium
sesquicarbonate, MEA (monoethanolamine) and TEA (triethanolamine)
may be used, although not being limited thereto.
The term "enzyme" used in the present disclosure means an enzyme
that can be used for cleaning. For example, one or more selected
from a group consisting of protein-degrading enzyme (e.g.,
protease, etc.), a lipid-degrading enzyme (e.g., lipase, etc.),
carbohydrate-degrading enzyme (e.g., amylase, etc.),
cellulose-degrading enzyme (e.g., cellulase, etc.),
mannan-degrading enzyme (e.g., mannanase) and a pectin-degrading
enzyme (e.g. pectinase) may be used.
In general, when the enzyme is added to the water-soluble polymer
solution in the form of a powder during the preparation of a
laundry sheet, the enzyme included in the sheet may be denatured
due to the drying at high temperature, which is essential in the
preparation process of the laundry sheet. As a result, the cleaning
performance of the laundry sheet may decrease due to decreased
activity of the enzyme.
In order to solve this problem, the enzyme is added in the form of
a granule in the present invention. Then, the activity of the
enzyme is not decreased during the use of the sheet even after
drying at high temperature for a predetermined time (see Table 3).
In addition, sheet-forming property is superior and the enzyme does
not ooze to the surface (see Table 2).
In the present invention, as the "bleaching agent", one commonly
used in cleaning may be used. For example, a perborate, a
percarbonate (e.g., sodium percarbonate), a perphosphate, a
persulfate, a persilicate, etc. may be used as an inorganic
bleaching agent and an organic peroxyacid including diacyl and
tetraacyl peroxide may be used as an organic bleaching agent,
although not being limited thereto.
Also, in the present invention, as the "bleach activator" one
commonly used in cleaning may be used. For example, one or more
selected from a group consisting of tetraacetylethylenediamine
(TAED), benzoylcaprolactam (BzCL), 4-nitrobenzoylcaprolactam,
3-chlorobenzoylcaprolactam, benzoyloxybenzenesulfonate (BOBS),
nonanoyloxybenzenesulfonate (NOBS), phenyl benzoate (PhBz),
decanoyloxybenzenesulfonate (C.sub.10-OBS), benzoylvalerolactam
(BZVL), octanoyloxybenzenesulfonate (C.sub.8-OBS) and hydrolytic
ester may be used, although not being limited thereto.
When the bleaching agent and/or the bleach activator is added to a
water-soluble polymer solution in the form of a powder during the
preparation of a laundry sheet as in the existing technology, they
may be activated by water contained in the water-soluble polymer
solution during the preparation of a sheet and, therefore, may not
fully exert their effect during cleaning. In order to solve this
problem, the bleaching agent and/or the bleach activator is in an
undissolved state in the present invention. Then, a large portion
of the bleaching agent and/or the bleach activator is activated
during cleaning and, therefore, provides significantly superior
bleaching performance as compared to when it is added to the
water-soluble polymer solution (see Table 3). In addition,
sheet-forming property is superior and the bleaching agent and/or
the bleach activator does not ooze to the surface (see Table
2).
In the present invention, as the "sterilizer/disinfectant", one
commonly used in cleaning may be used. For example, sodium
hypochlorite, hydrogen peroxide, urea peroxide, sodium
dichloroisocyanurate (NaCl.sub.3(CON).sub.3), potassium sulfate
((KHSO.sub.5).sub.2 KHSO.sub.4 K.sub.2SO.sub.4), calcium peroxide,
sodium tripolyphosphate, sodium acid pyrophosphate, etc. may be
used, although not being limited thereto.
When these components are prepared into a granule, they may be
prepared into a granule either alone or in combination with two or
more.
The laundry sheet according to the present invention may further
contain a fabric softener, a dispersant, an emulsifier, etc. in
addition to the above-described components.
More specifically, the laundry sheet according to the present
invention may contain a quaternary ammonium salt-based cationic
surfactant as the fabric softener. For example, one or more
selected from a dialkyl dimethyl ammonium chloride represented by
Chemical Formula 3, a dialkyl imidazolinium salt represented by
Chemical Formula 4, a dialkylamido quaternary ammonium salt
represented by Chemical Formula 5, an ester-quat, etc. may be
used.
##STR00001##
In Chemical Formulas 3, 4 and 5, each R is independently a
C.sub.1-C.sub.30 linear or branched, saturated or unsaturated alkyl
hydrocarbon.
As the fabric softener, a natural or synthetic cationic polymer may
be used. For example, one or more selected from cationic guar such
as guar hydroxypropyltrimonium chloride, hydroxypropyl guar
hydroxypropyltrimonium chloride, etc., cellulose
(Polyquaternium-10), polyquaternium series, a dimethyl diallyl
ammonium chloride polymer, an acrylamide-dimethyl diallyl ammonium
copolymer, a polyvinylpyrrolidone (PVP)-dimethylaminoethyl
methacrylate copolymer, an acrylic acid-dimethyl diallyl ammonium
chloride copolymer, an acrylamide-dimethylaminoethyl methacrylate
methyl chloride copolymer, a trimethylaminoethyl methacrylate
polymer, etc. may be used, although not being limited thereto.
Also, the laundry sheet of the present invention may contain a
dispersant. For example, the dispersant helps the water-soluble
polymer to be uniformly mixed with the active component for
laundering such as the cationic surfactant and improves water
dispersibility of the active component for laundering during the
dissolution of the film.
The laundry sheet according to the present invention may contain a
nonionic surfactant as the emulsifier. For example, one or more
selected from a polyoxyalkylene alkyl phenyl ether, a
polyoxyalkylene alkyl ether, a polyoxyethylene polyoxypropylene
block polymer, a polyethylene glycol fatty acid ester, a
polyoxyethylene sorbitan fatty acid ester, etc. may be used.
The content of the emulsifier may be 0-40 wt %, specifically 1-20
wt %, more specifically 1-10 wt %, based on the total weight of the
film after drying. If the content of the emulsifier exceeds 40 wt
%, flexibility may decrease because the amount of the fabric
softener, etc. adsorbed to a fabric is decreased remarkably.
Specifically, an emulsifier with an HLB value of 2-18 may be used.
This emulsifier makes it easier to prepare the sheet and allows all
the active components contained in the prepared sheet to be
released to and dispersed in water during cleaning. More
specifically, an emulsifier with an HLB value of 8-12 may be used
in this aspect. The HLB refers to the hydrophilic-lipophilic
balance.
The laundry sheet according to the present invention may further
contain a perfume, an preservative, a stabilizer, a pigment or an
antimicrobial agent in addition to these components.
The laundry sheet according to the present invention may have a
tensile strength of specifically 0.5-15 kgf/cm.sup.2, more
specifically 1-12 kgf/cm.sup.2. If the tensile strength of the
laundry sheet is lower than 0.5 kgf/cm.sup.2, the laundry sheet may
break easily during transport or use. And, if it is higher than 15
kgf/cm.sup.2, fast dissolution property may be unsatisfactory.
The laundry sheet according to the present invention may have a
thickness of specifically 1 m to 1 cm, more specifically 5 m to 0.5
cm. If the thickness of the dried laundry sheet is smaller than 1
m, an enough amount of the active component cannot be supported,
the film strength is decreased and it is difficult to achieve the
desired performance. And, if thickness of the dried laundry sheet
exceeds 1 cm, fast disintegration property and fast dissolution
property are unsatisfactory and it is difficult to obtain a uniform
water-soluble film.
Because the laundry sheet according to the present invention is
completely dissolved in water after being used, an additional
process of removing the laundry sheet is unnecessary. That is to
say, the water-soluble polymer forming the matrix of the sheet is
removed by being dissolved in water and the component contained
therein exerts its effect by being dissolved or dispersed in the
water.
In an exemplary embodiment, the present invention provides a
multi-layered laundry sheet wherein one or more film or laundry
film is stacked to form a multi-layered structure.
In an exemplary embodiment, the present invention provides a
laundry sheet wherein a film or a laundry film prepared using a
film-forming water-soluble polymer is further stacked on one or
both sides of the laundry sheet.
In addition, the present invention provides a laundry product
containing the laundry sheet according to the present invention.
The laundry product may include the laundry sheet according to the
present invention itself and a laundry pouch, a laundry bag, a
laundry envelope, etc. containing the laundry sheet according to
the present invention. The laundry pouch, laundry bag, laundry
envelope, etc. may be prepared such that it contains two or more
laundry sheets according to the present invention and an inner
space is formed, so that a desired material is added in the inner
space, such that the sheet can exert its effect as it is dissolved
or after it is dissolved.
Advantageous Effects
The present invention provides a laundry sheet which is completely
dissolved in water and, thus, is not necessary to be removed after
cleaning.
The laundry sheet of the present invention exhibits superior
cleaning performance and is convenient to use. In addition, the
laundry sheet has superior storage stability.
The laundry sheet of the present invention, which contains a
component exerting an effect by reacting with water in the form of
a granule, can provide a more superior cleaning effect during
cleaning.
DESCRIPTION OF DRAWINGS
The accompanying drawings illustrate a preferred embodiment of the
present disclosure and together with the foregoing disclosure,
serve to provide further understanding of the technical features of
the present disclosure, and thus, the present disclosure is not
construed as being limited to the drawing.
FIG. 1 schematically shows an exemplary embodiment of a laundry
sheet containing an active component for laundering in an
undissolved state (granule form).
FIG. 2 schematically shows an exemplary embodiment of a laundry
sheet containing an active component for laundering in an
undissolved state (granule form), wherein the granule protrudes
from the surface of the laundry sheet.
FIG. 3 schematically shows an exemplary embodiment of a laundry
sheet in which two sheets of a film prepared according to an
exemplary embodiment of the present invention are stacked.
Specifically, a laundry sheet 2 is shown wherein a film is further
attached to a laundry sheet in which an active component for
laundering in an undissolved state (granule form) is distributed on
a first film 10. In the laundry sheet 2 shown in FIG. 3, the active
component for laundering exists in an undissolved state between the
films. One or more of the films constituting the sheet 2 may be a
laundry film.
FIG. 4 schematically shows an exemplary embodiment of a laundry
sheet 3 in which three sheets of a film prepared according to an
exemplary embodiment of the present invention are stacked.
DESCRIPTION OF MAIN ELEMENTS
1: laundry sheet 2: laundry sheet in which two sheets of a film are
stacked, as an exemplary embodiment 3: laundry sheet in which three
sheets of a film are stacked, as an exemplary embodiment 10: film
containing water-soluble polymer 20: active component for
laundering
MODE FOR DISCLOSURE
Hereinafter, embodiments of the present disclosure will be
described in detail to help understanding of the present
disclosure. However, various modifications and changes could be
made to the embodiments of the present disclosure, and it should be
understood that the scope of the disclosure is not limited to the
following embodiments. The embodiments of the present disclosure
are provided to persons having an ordinary skill in the art for
more complete description of the present disclosure.
PREPARATION EXAMPLES
Comparative Examples 1-3
A 20 wt % PVA solution was prepared by adding 200 g of PVA (degree
of saponification: 86.5%, average degree of polymerization: 500) to
800 g of distilled water and dissolving at 80.degree. C. for 4
hours. After adding the active components described in Table 1 to
the prepared PVA solution, they were dissolved by mixing with a
mechanical stirrer. After loading the prepared PVA solution onto a
release film, a film with a predetermined thickness was prepared
using a film applicator (Elcometer). Then, a laundry sheet
(thickness: 0.01 cm) was prepared by drying in a drying oven at
105.degree. C. for 10 minutes.
Examples 1-3
A 20 wt % PVA solution was prepared by adding 200 g of PVA (degree
of saponification: 86.5%, average degree of polymerization: 500) to
800 g of distilled water and dissolving at 80.degree. C. for 4
hours. After loading the prepared solution onto a release film, a
film with a predetermined thickness was prepared using a film
applicator (Elcometer). Then, after spreading active components in
the form of a granule onto the sheet, a laundry sheet (thickness:
0.01 cm) containing the active components was prepared by drying in
a drying oven at 105.degree. C. for 10 minutes.
TABLE-US-00001 TABLE 1 Examples Comparative Examples (Unit: wt %) 1
2 3 1 2 3 Polymer PVA.sup.(1) 40 40 40 40 40 40 matrix Active
Surfactant.sup.(2) 48 48 48 48 48 48 components Builder.sup.(3) --
-- -- 10 -- -- (dissolved Enzyme.sup.(4) -- -- -- -- 10 -- in
sheet) Bleach -- -- -- -- -- 10 component.sup.(5) Granular
Builder.sup.(3) 10 -- -- -- -- -- active Enzyme.sup.(4) -- 10 -- --
-- -- components Bleach -- -- 10 -- -- -- component.sup.(5)
Additives Perfume and 2 2 2 2 2 2 others Total 100 100 100 100 100
100 (Note) PVA.sup.(1): polyvinyl alcohol, degree of
saponification: 86.5%, average degree of polymerization: 500
Surfactant.sup.(2): SLS (sodium lauryl sulfate) Builder.sup.(3):
sodium carbonate Enzyme.sup.(4): protein-degrading enzyme
(Savinase, Novozymes) Bleach component.sup.(5): sodium
percarbonate
<Test Example> Evaluation of Sheet-Forming Property and
Performance
The sheet-forming property and performance of the laundry sheets
prepared in Examples 1-3 and Comparative Examples 1-3 were
evaluated by the methods described below. For the performance
evaluation, cleaning performance for contaminated fabric according
to the Japan Laundry Science Association, cleaning performance for
protein-contaminated fabric and bleaching performance for
tea-contaminated fabric were evaluated.
(Evaluation of Sheet-Forming Property)
The sheet-forming property of the PVA film sheets prepared in
Examples 1-3 and Comparative Examples 1-3 was evaluated through
visual inspection. The result is given in Table 2.
.circleincircle.: Sheet formulation is flexible and excellent
without oozing.
O: Sheet formulation is flexible but a liquid component slightly
oozes out.
.DELTA.: Sheet flexibility is insufficient and slight oozing
occurs.
X: Sheet formulation fails, and much liquid component oozes
out.
TABLE-US-00002 TABLE 2 Examples Comparative Examples 1 2 3 1 2 3
Sheet-forming .circleincircle. .circleincircle. .circleincircle. X
.largec- ircle. .DELTA. property
As seen from Table 2, Examples 1-3 showed superior sheet-forming
property, whereas Comparative Examples 1-3 showed decreased
sheet-forming property as the contents of the active components
dissolved in the sheets were increased. In particular, sheet
formation failed when the builder component was mixed in the form
of a liquid as in Comparative Example 1.
(Evaluation of Cleaning Performance)
Cleaning performance was evaluated using a washing machine of the
same condition and tap water. Cold tap water was used for the
cleaning. A wet artificially contaminated fabric prepared according
to the Japan Laundry Science Association and the
protein-contaminated fabric EMPA 116 were used to evaluate cleaning
performance. Also, a tea-contaminated fabric BC3 was used to
evaluate bleaching performance. The evaluation was conducted by
attaching the contaminated fabric to a cotton T-shirt. Also, a
comparative evaluation was conducted by a statistical method using
16 pieces of contaminated fabrics having a size of 5 cm.times.5 cm.
In this instance, the WB value representing a whiteness index of
the contaminated fabric was measured using a color difference meter
before and after the cleaning. The laundry sheet prepared in each
example was cut to a size of 20 cm.times.15 cm, and 2 pieces of a
detergent were used. At the beginning of cleaning, the laundry
sheet and the detergent were put into a washing machine together
with the contaminated fabrics, cleaning was done under the
conditions of a standard program (cleaning for 20 minutes, rinsing
twice) of the washing machine and a middle water level, and after
dehydration, the contaminated fabrics were dried in a constant
temperature and humidity room (25.degree. C., 20% RH) for a week
and then ironed. Then the WB value was measured using the same
color difference meter. The cleaning performance was calculated
from the obtained result using the Kubelka-Munk equation expressed
by Equation 1. The result is given in Table 3.
.times..times..times..times..times..times..times..times..times..times..ti-
mes. ##EQU00001##
In Equation 1, R.sub.s denotes the surface reflectivity of the
contaminated fabric, R.sub.c denotes the surface reflectivity of
the contaminated fabric after the cleaning process, and R.sub.o
denotes the surface reflectivity of the white cotton fabric.
TABLE-US-00003 TABLE 3 Examples Comparative Examples Cleaning
performance (%) 1 2 3 4 5 6 Contaminated fabric prepared 73 67 70
59 58 58 (Japan Laundry Science Association) Protein-contaminated
fabric 68 75 63 42 42 22 (EMPA116) Tea-contaminated fabric 75 71 83
43 35 35 (BC3)
As seen from Table 3, Examples 1-3 wherein the active components
were added in the form of a granule showed superior cleaning
performance.
INDUSTRIAL APPLICABILITY
The present invention provides a laundry sheet which is completely
dissolved in water and, thus, is not necessary to be removed after
cleaning. The laundry sheet of the present invention exhibits
superior cleaning performance and is convenient to use. In
addition, the laundry sheet has superior storage stability.
* * * * *